EGU21-12578
https://doi.org/10.5194/egusphere-egu21-12578
EGU General Assembly 2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.

Diffraction imaging and depth-velocity inversion with 3D P-Cable seismic data

Alexander Bauer1, Benjamin Schwarz2, and Dirk Gajewski1
Alexander Bauer et al.
  • 1University of Hamburg, Institute of Geophysics, Hamburg, Germany (alex.bauer@uni-hamburg.de)
  • 2GFZ German Research Centre for Geosciences, Potsdam, Germany

Most established methods for the estimation of subsurface velocity models rely on the measurements of reflected or diving waves and therefore require data with sufficiently large source-receiver offsets. For seismic data that lacks these offsets, such as vintage data, low-fold academic data or near zero-offset P-Cable data, these methods fail. Building on recent studies, we apply a workflow that exploits the diffracted wavefield for depth-velocity-model building. This workflow consists of three principal steps: (1) revealing the diffracted wavefield by modeling and adaptively subtracting reflections from the raw data, (2) characterizing the diffractions with physically meaningful wavefront attributes, (3) estimating depth-velocity models with wavefront tomography. We propose a hybrid 2D/3D approach, in which we apply the well-established and automated 2D workflow to numerous inlines of a high-resolution 3D P-Cable dataset acquired near Ritter Island, a small volcanic island located north-east of New Guinea known for a catastrophic flank collapse in 1888. We use the obtained set of parallel 2D velocity models to interpolate a 3D velocity model for the whole data cube, thus overcoming possible issues such as varying data quality in inline and crossline direction and the high computational cost of 3D data analysis. Even though the 2D workflow may suffer from out-of-plane effects, we obtain a smooth 3D velocity model that is consistent with the data.

How to cite: Bauer, A., Schwarz, B., and Gajewski, D.: Diffraction imaging and depth-velocity inversion with 3D P-Cable seismic data, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-12578, https://doi.org/10.5194/egusphere-egu21-12578, 2021.

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